The reasoning also for 90 degree trenches is also so shrapnel doesn't continue down the tunnel it will embed itself in the wall of the first corner created.
Trenches also have 90-degree corners because they provide cover when the enemy raids the trench, A corner will also deny the enemy a long line of sight.
@@Dhunter83 Both valid points, and I scrolled down to the comment section because I was *sure* that they'd fuck up these two aspects. Thanks for confirming my hunch. Sad thing (or mindboggling thing?) is that we nowadays have "simulation" video games where such elemental factors play no role. Instead we learn that you exit you plane in mid-flight, shoot an enemy plane with your Panzerfaust (or whatever, "Panzerfaust" or "Panzerschreck" are just ubiquitous in these games because they sound so badass German super-science), and then board your plane again. Was. Der. Fick.
There are several reasons to dig trenches that way. They might dissopate the blast wave from a shell, but most casualties did not come from blast waves, but from shrapnel, and shrapnel will most certainly not go around corners. A second reson is that if the enemy manges to enter your trench, they will not have a clear shot down the length of the trench. One reason the trenches were dug in straight sections with 90⁰ angles is that they were often dug under fire, and each section needed to join up with another section of trench, dug by another group of soldiers. Digging a wavy trench like a sinewave, is really difficult because you have no easy reference point, and you don't want to climb out of there to see if you are getting it right. With the pattern they used, you can dig 30 yards, turn 90⁰ left, dig 30 yards, turn 90⁰ right, and so on. The soldiers can work by measuring tape and a compass, no need for advanced mathematics.
@@petergerdes1094 They reason they didn't cut corners was because these trenches almost always had the sides reinforced with planks/logs/concrete to prevent them caving. It's a lot easier to attach to planks/logs/concrete at 90 degrees then it is to bend planks/logs/concrete around a curve. Any man with a T square can make a corner, but only a highly skilled craftsman can make a curved line with wood or stone.
When I was in the Army we were told that angling trenches was to prevent shrapnel spread. Blast needs to go 'somewhere', and follows the line of least resistance, so we presumed that the angles would also help, but not by absorbing blast, rather by slowing it laterally, this meaning there would be less resistance to it vertically = it goes up... 👍
Shockwaves travel further to get to you or through a wall of dirt Another reason especially with anything more than muzzloading can clear a trench fairly hastily if the trench is straight, they can fire down the entire length
When you were in the Army, did the still teach trench warfare to general infantry? Reason I'm asking is I with Ukraine, trench warfare has become increasingly relevant; I saw a post from a foreign fighter (not sure if they were a Solider or Marine) stated that when serving in the US, he was never taught anything about trench warfare because the US tries to avoid that situation entirely (and the focus of the last 2 decades was on COIN operations). Edit: Shorted a sentence for clarity.
I'm assuming that they also taught you that you should not be able to see a third section of trench from the one you are in. If you look at the "serpentine" trench, you can see a straight line through the curve to the next straight. My reading as a kid told me trenches on the Western Front zig-zagged in basically uniform lengths, not the little kinks between straights seen here.
@@aaronleverton4221 hard corners give soldiers cover to peak round when others reach it instead of being fired upon as soon as they reach your trench Zigzag trenches are better for attaching a position, using full bends leaves some parts easily fired upon from a bit of height Zigzags give some cover at all times when advancing
@@apokkalyps6yeah, maybe we could have learned from history where you have periodic attacks on Russia from the west, be it by Swedes, Teutons, Polish-Lithuanis, France, Great Britain, Germany or US... the take away here would be the folks who use swastika clad aholes are no better then them...
Haven't heard of the corners being used to protect against blast wave, but I have heard that it helps against shrapnel and it is easier to protect your trench against the enemy too. If the enemy took over a straight trench then they could easily shoot everyone in it, but if it has corners, then you take over only one corner at a time.
Originally the trenches were built zig-zag so you couldn't just shoot a cannon straight down the line. Especially because the trenches (saps) were dug to get close to castle walls during sieges so you wouldn't get everyone obliterated by cannon fire.
Without watching the video yet. I was about to come to say exactly same. Corners protect against shrapnel and enemy bullets if they get to the trench. I don't think it can stop blast wave ever, in best case slow it down maybe. But shrapnel and bullets it will stop for sure. Those can't make it around the corners. Of course same way those corners help to protect the enemy that has got in to the trench, but it provides small chance of survival for both sides compared to none in straight trench. In direct fire is anyway one of the used methods even in modern days and shrapnal from those. And to be honest situation is pretty bad if enemy is in the same trench that one tries to prevent them to getting to.
@@EsaNuutinen it is even more important against shrapnel than against blast wave, since the lethal radius of shrapnel goes much further than the blast wave's lethal radius
Yeah, i always disliked the "2 steps forward, 1 step back" editing formula of TV. I used to watch a lot of Mythbusters and River Monsters back then, but the formula got really tiresome. At least you can skip through a lot of it now, but i have been thinking about editing my own versions of shows sometimes, either by cutting out Tory, Kari and Grant if they were doing something useless, or vice versa. And indeed, cutting away all of the "coming up" and the post ad-break recaps. But the other channel does have some "Best of" episodes that cut away a lot of the fat. But they even turned a control test into a cliffhanger in this episode, which actually made me go: "Really?? A control test cliffhanger, come on." I mean, i get it, it's a car crashing down, spectacular footage, but still, it was still only just the control.
I originally watched these on German TV, it was a completely different experience 😆 Just like there's barely any canned laughter in the sitcoms broadcast on German TV. I think I remember one in the 90s where they didn't have any of that, just a lot of awkward pauses 😂
Haven't ever heard it suggested before that the purpose was to stop blast waves. My understanding is trenches are angled to limit casualties from shrapnel and enfilading fire along an entire position should it be flanked.
I think the thing people are getting hung up on in the straight trench is that they aren't thinking about the situation right. The explosion and its pressure wave are very fast, and the straight trench is effectively a giant resonating chamber for it. The similar experiment in air and sound would be a long tunnel and echos, compared to an anechoic chamber compared to an open field compared to a normal room. A large open room is not the same as an open field, because it does eventually have walls that rebound sound. An anechoic chamber is the closest compared to an open field because it dampens and attenuated sound waves. The long, sealed tube will be the most echoic, because it has no place to dissipate sound. This is the effect of the trench, it magnifies the blast by confining it, the other two bent trenches diffuse the blast upwards and into the earth, cutting out a lot of the overpressure the straight trench will feel.
Yeah, they effectively invalidated the experiment with their trench construction. Not only did they fail to account for the shockwave reverberating within the trenches, they built 2 with plywood panels and 1 without, meaning that the shockwave would behave differently in 2 of the 3 trenches.
Tbh, this is the first time I ever hear about trench corners being about pressure waves. To me it was always about shrapnel, which undoubtedly will be stopped by any corner whatsoever.
@@literallyjustgrass Well, there is some point to it in the case that enemy infantry enters you trench. If you had one long trench, a single machine gunner could mow down everyone inside. Apart from that, line of sight is always also a pathway for shrapnel, so you weren't entirely wrong.
Just seems like an all-round good idea really. Reduces the pressure wave, reduces the travel distance of shrapnel, inhibits line of sight for attackers, prevents strafing attacks from above, allows sections to hold out and be used for counterattacks even when others fall.
Good question to ask. To be honest, I thought they were effective at higher speeds. Fascinating. "For unbelted occupants the effectiveness goes to zero or becomes negative above 40 kph (25 mph) for MAIS 3+, and for belted occupants the effectiveness stays positive but with significantly lower magnitude for speeds above 40 kph (25 mph)." pubmed.ncbi.nlm.nih.gov/16210197/
It won't. I worked on polymer "springs," for a safety device years ago. The problem is even with an ideal material with perfect compression ratios at the speeds they were testing the body needs to decelerate over a longer distance than is possible in a car crash. The balloons/airbags/ are decelerating the body to a stop over a few inches... your organs/brain just slam into your ribs and skull. You wont go through the windshield or hit the stirring wheel and have external bleeding necessarily, but your skeleton is the backstop for the liver, ribs, kidney, heart brain, etc...
It's probably just easier to make sure you don't continue a straight path through a serpentine when digging with sharp corners. Dig Width x and make a 90 degree bend continue 2times as long as width x and start another 90 degree bend. Making things round serves no extra purpose and would introduce errors, so 90 degree bends are just more efficient. Also note that German trenches are NOT 90degree walls, but tapered down. Less digging, roomy for your upper body, supports leaning and bracing to shoot and allows pressure and shrapnel to release up, rather than amplify down.
These guys are remarkable not only for studious study, but the ability to work together and accept a new idea from a member is to be tried. Excellent science.
Idk how the numbers at 47:45 makes sense. 76, 60 and 397 are all in a straight line, so shouldn't all of them have similar numbers? It's not before the second set of numbers where we should start to see real differences, no?
@@MushookieMan I don't really think so. The blast wave at the very end of the straight trench is down to 21 psi. Even if all of that comes straight back, you'd expect to see 97psi (if you use the 10ft value from the curvy-cornered trench and assume that none of it was reflected back). I'd bet the 397 was caused by some piece of lumber or something hitting the measuring apparatus.
I had a close look a the numbers. The 397 is clearly an outlier. The 60 vs 76 show that there's a 20% margin of error in the strength of the shock wave that goes down the trench. The 60 is right before a sharp corner, from which most of the shock wave would be reflected, and the 76 is before a round corner, which should reflect less of the shock wave back (if that even has an effect on the 10ft numbers). (Also, 20 ft along the straight trench you have 65psi, while you have only 60psi after only 10ft along the sharp-cornered trench. That also can't be the case without some variability in the shock wave strength.) The remaining numbers along the curved and sharp-corned trenches are well within that 20% margin of error of each other, meaning that we really can't be certain that the corner shape helped. But here's the actually interesting result: If you compare the open ground results versus those in the two cornering trenches, you see that the numbers inside the trenches are still higher (and by more than 20%). This means that the trenches still "conduct" the pressure wave. As in, the pressure wave can't just have "jumped out" of the trench, traveled over top of the cornering section, and gotten refracted or reflected back into the trench. Meaning both the sharp-angled and the curvy corners are far from perfect.
Somehow that charge was too powerful Possibly an incorrect mix or perhaps substituted a different explosive If they only planned the 3 trenches and tacked the flat ground “control” at the last minute the substitute would probably have been a plastic explosive instead of a less common granular high explosive that would be more ww2 authentic
Can anyone explain why the first tunnel's explosion produced such a high PSI at 20ft compared to the other two? Surely all three trenches are the same up to 20ft, then they turn - so my assumption is that the pressure wave would be the same up until the first corner, but clearly not?
Doesn't make sense to me. Doing the math on the reduction in pressure the straight trench is reduced by a factor of 1/20th compared to 1/10th on the others.
The reason why the blast pressure in the straight trench was so much higher than in the open-air test was because of the internal reflections of the blast wave in an enclosed space. In the open air where the blast wave can expand in almost 360º, it follows the inverse square law like a sound wave's amplitude. However, in the trench, all that energy is redirected and focused down the tube, almost like speaking through a long tube will amplify the volume in a single direction.
@@ChrisvanderMerwe_cw3 I get that, but my point is that, up to 20ft, the three trenches are identical, right? So why are the blast pressures so radically different between them
I think it's about ripple/scattering and air compression. As the wave moves through clean air unhindered, it seems to be the most potent. But maybe if the wave nears a wall, air pressure starts building up from being pushed towards the wall, and in turn pushing back a little on the wave or creating a bit of an air cushion, on top of also colliding with the wall. The bouncing back might also explain why the straight trench seems to lose so much bite so quickly, as it just keeps on moving relatively unhindered. But then i wonder if all the tests moved at the same speed, as in, did the sensors go off at the same intervals, or was the straight trench pressure wave quicker than the rounded or squared one?
@@ChrisvanderMerwe_cw3 Yes that would certainly account for some increased pressure but not 10 times more. The exact same distance of 20 feet straight is in all the examples but only one of them has a 10x increase.
great episode thanks for posting this . i had to pas it along to the mythbusters group so others can watch it as well its great to see the full episodes i hope you make more of them available to be watched here in the usa without having to get a vpn to watch them . rest in peace sir Grant i wish mythbusters had a Star on the walk of fame
I know the trench myth is the main focus in the episode, but it really didn't seem like the three of them understood airbags at all. You're not trying to stop the person, you're trying to slow them down, and you're trying to do it from full speed to a stop. Dropping the car was more or less fine, but the weight tube to do the mini tests starts from nearly rest. They also seemed to think the balloons popping was a bag thing when it's the other way around: The balloons popping gives more time to decelerate the person/weight. I think it would've been more interesting if they understood that before doing the tests, because this felt like an "egg drop" challenge assignment for school when they hadn't paid attention during class
It's not that the balloons popping is bad, but that they're popping before they're able to have much of an effect. However, they definitely used that test incorrectly. In the control, the weight has the entire length of the tube to accelerate due to gravity before it faces any resistance. After that, it meets its first resistance almost immediately, meaning the higher you stack the balloons the lower the force applied to them at first contact. The balloon animals were literally touching the weight mechanism when it was released. A nearly useless experiment.
I have friends in Ukraine for whom this is a very practical concern, thank-you for reposting this. People need to be reminded this is a thing today, not just in WWI and WWII.
I mean in this day and age its all sense less, you can spend a week in a foxhole, think your safe to come out and in a second a drone will touch down and kill you. If any thing, the Ukrainians are more than adapt at building trench networks, just like the Russians are.
@@MytyaPrykhod There is also a (small) chance that he is a Russian volunteer fighting for Ukraine. A Czech firearms instructor buddy of mine did train a group of Belarusian volunteers that had joined the Ukraine side back in the early days of the war. So I suspect there will also be some Russians.
@@STURYANPHUAYEWLIANG Yeah I've seen combat footage from Ukraine where the Ukranians and Russians are in the same trench no more than a few meters away from eachother but beacuse the trenches aren't a straight line they can't shoot eachother and they can sit in the same trench holding the angles and throwing grenades at eachother for half an hour or more. Sometimes it is only decided by a fpv drone coming and doing a precision strike, or one side retreats rather than going around the corner or climbing out of the trench towards the enemy since it means very likely death.
For the ballons tests: in the control, the driver (with seatbelt) experienced a 150G, after the improved balloons test, the clown only experienced a 130G load. Meaning that it would be more beneficial to tightly pack some strong balloons in front of you instead of wearing a seatbelt!
2:22 the germans, or anybody, never thought corners were for shockwave protection. when an artillery shell explodes it throws metal shrapnel everywhere. a corner stops the shrapnel from flying straight down the trench, killing or wounding everyone. instead only the people in the section that got hit catch shrapnel.
But... trenches rarely had flat walls. They had parapets, dugouts, drainage ditches, in-wall bunks, ammo shelves, sandbag steps, ladders, and, of course, bodies.
Yeah, and they should have tested with an actual air bag as a control, I have a feeling it wouldn't fare that much better. Looking at the numbers alone, going from 500-600 or whatever it was down to 150 should have made the myth at least plausible.
I was thinking the same thing. Their control had a seatbelt also not be sufficient to survive. So their test was trying to show that balloons were better than modern safety equipment, not that it could save your life.
Also, that their last test were worse than the big balloons were telling. In their shop test, they effectively went for the stiffest setup, as that would hinder the dropping weight accelerate as it was dropped just above the balloons. The weight should have been at significant speed compared to the acceleration when the impact happend. The further distance the body travels during stopping, the less g's, so the big balloons where the nose just barely touched the windscreen was about as perfect an impact as one could hope for, no matter the safety equipment. They were basically testing to see if they could make it safe, while doing a drop height where the total crumble zone was insufficient to ensure survivability no matter how well cushioned the passenger was.
If you want to reduce shockwave and pressure, you should give a " V " shaped trench a try. Rectangular trench funnels the blast wave, amplifying it. " V " shaped trench projects the blast wave outside the trench. I pretty sure it will make a significant difference.
Containing blast is one thing. Containing shrapnel is quite another. Most angles will contain shrapnel. To contain or dissipate blast you need the equivalent of a silencer on a gun. That is lots of paths to exit the blast safely before it propagates down the trench line,
To stop shrapnel you want vertical trench walls perpendicular to the direction of the enemy, a corner like that results in a piece of trench that goes towards the enemy, which is bad for shrapnel protection. Shrapnel not fragments, are often used synonymously today but if you talk about a WWI context real Shrapnel shells were in use and popular during the early part of the war. They are fundamentally a canister with bullets fired from an artillery piece that separate in the air close to the target by small bursting changes. Practically it is like a large shotgun that is fired from the air at a relatively flat angle toward the ground. A deep trench with a vertical wall defeated them and they became obsolete during WWI High-explosive shells produce fragments, not shrapnel. The corners are to stop the pressure wave and the fragment from a shell with high-explosives, not shrapnel The difference between fragments or shrapnel might be irrelevant in today's context but is very important in a WWI context.
@@target844corners prevent fragmentation, which is what the guy is talking about. If a shell lands inside the trench, the fragments shred that section but go no further as they embed themselves in the corner wall. The corner did not significantly degrade it's defensive capability from ground fire, since people in the trench would still be below the level of the ground
It's also to help the defenders and prevent an enfilade. If the enemy captures one end of a straight trench -- they own that trench as far down as they can shoot. But if the trench has corners, the trench can be defended from the attackers at each corner.
The "plausible" rating on the trench thing when the difference was literally just one PSI at each measure point between the sharp and rounded corners... That's the definition of margin of error.
Also, there is no reason for the 20 feet pressure to be much higher in the curved trench compared to the sharp one. th-cam.com/video/Milnou63Dyg/w-d-xo.htmlsi=6iV9zJeW37dmzM3O&t=2889
Was thinking the exact same thing 1-2 PSI is a margin of error. I'm also confused as to how the straight trench amplified the blast 10x within 20 feet but the other two were significantly lower within the same 20 feet straight. It seems that the 50ft mark is roughly 10% of the 10 feet mark except for the straight where it's only 5% of the initial blast.
There's proceedural and other errors (often serious) in all their experiments, which invalidate the vast majority of their results. One day, people will learn that they are not authorities and this isn't science, no matter how many times they use that word.
They messed up when they decided the curved trench wouldn't have wood all the way. It's very possible that the bare dirt absorbed more pressure than the wood panels. Given what they are capable of making, they should've made curved wood panels.
4:30 "This is all the Baby oil San Fransisco had today" ... This sentence gave me whiplash as I was watching this classic episode. Man, who would have ever thought such a mundane and intentionally silly sentence would be so creepy many years later... In no ways is this an accusation, but it's more just a sad example of how context can change simple perceptions.
Trench corners were not just for subduing explosions, but also to stop rifles being fired down the length of the trench and make the trench easier to defend against an attacker who had got in to the system.
Something about the straight trench doesn't add up. For the control and the two cornered trenches they all follow a pattern roughly 30ft 1/3, 40 ft 1/5 and 50ft 1/10 however the straight is 30ft 1/6, 40ft 1/10 and roughly 1/20th of the blast at 50ft. Mathematically the straight reduces the blast more but for some reason the initial blast was significantly higher.
It might have something to do with scattering? I also thought that the initial blast seemed too great compared to its dropoff. But, seeing how the other 2 trenches had similar dropoffs, i think that with the straight trench the harmful waves keep bouncing away from the blast relatively unhindered, whereas the other 2 trenches provide a little bit of a "noisy feedback" because of the opposing angles. Because, it's designed to stop the wave from moving forwards, so, some of it will be scattered back, but altogether less harmful than an unhindered explosion.
@@Games_and_Music Great theory however doesn't account for the above ground sample. it too followed the same drop off as the cornered trenches. More so the first 20 feet of all the trenches is the same but only the straight one had 10x the PSI compared to the control/above ground while the other two trenches were roughly 2x.
@@DiustheZ Fair point, the control would've been the worst if unhindered alone was the answer. Maybe, as i just "realized", it could also be like a firecracker effect. Where the gunpowder itself ignites fairly powerfully, but it becomes a lot more when confined, packed tight. That the straight trench also acts a bit like a barrel, an air cannon or something, I would also not want to be jumping over that trench when the explosion goes off. Not sure what bent firecrackers will be like, so i'm not sure how well the analogy works. Just throwing spaghetti against the wall.
might be a matter of the shockwave bouncing back and forth along the length of the straight trench causing interference with itself that amplify the pressure at certain points. While both the bendy trenches would reduce that by bleeding off energy round the corner each time the shockwave hit the wall at the bend and bounced back
@@WhichDoctor1 That's more than certainly the cause of the increase over the above ground control. Problem with that explanation purely for the straight trench 10x increase is the 20ft straight is exactly the same on all three trenches. The blast would be travelling one way through the trench and wouldn't travel backwards. Theoretically the blast should be the same on all the 20ft straights regardless of what is after it. Once the initial blast passes the sensor it doesn't come back.
I know everyone's saying the shrapnel is what really matters, but I think shockwaves are no joke. I remember in 9th grade I was playing sports on the school field and I was right in the middle when a powerline transformer blew from the field edge. To my surprise, I felt a pretty hard _THUD_ hit my chest from the blast wave, and that was just a powerline transformer.
That's why the trenches aren't completely straight, to stop bullets and fragments. Those two it doesn't matter if the corners are sharp or a bit rounded. The blast pressure of a shell is kind of insignificant compared to fragments, so even if the sharp corners do make a difference to the blast I'm not sure if they really matter much overall.
It's pretty terrifying thinking about the energy equivalence driving at a 'mere' 35mph with the speed you achieve dropping 42 feet vertically onto your face.
I've been in a restored German trench on a WW1 battlefield. It was a sine wave with woven wicker wall linings. The British trenches were the ones with ninety degree corners and corrugated roofing iron walls.
i agree it seems high. But i think it's right that it is higher in the straight trench because in the angled trenches there is relatively less resistance for the pressure to go vertical.
They likely took the wrong measurement from the 20ft sensor in the straight trench. The blast probably went through the sensor initially, but then rebounded off of the end of the trench and came back. At the same time, the blast also rebounded off the wall behind the explosives and came forward, for some reason meeting there most strongly. That was likely the highest reading from that sensor, but also probably not the first reading. I would bet that if we saw the full reading from the sensor it would have jumped to around 60 before spiking to 400 a few milliseconds later.
Waves can have additive and destructive interference. It might be that the sensor was exactly on a peak where all reflections added up. Back wall, end of the trench and both sides. It is a lucky shot but not impossible
As for the main myth: The place I live in is fairly angular, the hallway looks a lot like those 90 degree trenches. And airwaves travel through it flawlessly in one direction. I can follow entire conversations held at the other end of the apartment but no one even hears me scream. Smells too, they propagate throughout the entire place and die in my room
I think the trench "myth" deserves better than plausible. In fact, I think if you had added a ballistics gel dummy with waterfilled cavaties inside of it at the far end of each trench, it would have gotten a passed-stamp. Also, another reason for adding bends to a trench is that it slows down attackers trying to clear it when they have to move carefully due to not having good visuals around the bends, as well as providing the defenders with defensive points negating attempts to clear the trench system out.
WWI trenches often had wood reinforcement on the sides, It is a lot simpler to have sharp corners then any curved variant, just put a vertical pole in the corner and have the horizontal planks behind it. You can do that with other angles than 90 degrees too, it will just not be a curved corner. Wood on the wall prevents them collapse in from for example rain. It also provides better protection from both Shrapnel shells or the relatively primitive time fuzed that could be used to airburst shells. It also makes it possible to have a narrower trench. The flatter the trajectory of a shell the header it is to get into the trench if it is narrow with vertical walls. There is a reason mortars with a trajectory that is close to vertical when they hit the target become popular
@@target844 I wonder is not a negative to wood reinforcement that it produces more shrapnell compared to dirt when hit? Like shattered wood flying all around at a high speed?
@@serganta8861 Not really. The mortar or artillery shell would have the most shrapnel and would almost certainly kill anyone in the section of trench it landed in. Past the 90 degree corner, the damage to the wood would be negligible. It's also worth noting they used plywood instead of thicker, firmer planks. Plywood is much easier to break.
The myth they were testing wasn't how useful corners were (since their application against shrapnel and gunfire is obvious), they were testing whether or not those corners had to be *sharp* or not.
I mean... with a difference of 1 PSI, I don't imagine it would make THAT big a difference. If you're the poor sod whose trench got a direct hit around the corner, you'd probably just be happy you weren't a few meters down the line.
It seems so, but i guess the big one left out is the airbag. I guess crashes are a lot more lethal without the airbag. I thought that cars should be tested to be safe in crashes at certain speeds, 35 doesn't seem to be excessively fast, but yeah, the airbag might be the big difference.
they said they chose to do it at that height because in the myth they were at normal driving speeds, which the team assumed to be around 35mph (see 10:25) -- their calculations supposedly showed that dropping the car from that height would result in that speed at impact (Tori mentions it at 33:02)
@@LophoWilli Tori and the narrator talk about this at 11:35; they said it's easier/safer to perform the test in this manner than just have a car floor it towards a wall. Also, the directions of the forces acting on the driver/passenger in this test would likely be similar to those experienced in an actual car crash (in both cases the force would act from the front of the car inwards, acting to push the passengers into their seats)
I crasht my car at 35 mph headson to a tractor and im stil allive without seatbelt or airbag, hit my head in the windshield tho. Still enjoying the headaches today.
A bend waveguide dissipates energy from the guided wave... This is true for any type of wave through any type of waveguide. Be it an optical fiber, a grammophone or in this case a trench. They could do the experiment also with a sound source but explosions are simply wayyy more fun.
4:34 Oh I think I know where all the baby oil went 💀
I knew I would find a comment mentioning this. Thank you
YES
I was OMW here to mention that. 😀
aint no way lmao
They were ahead of their time.
The reasoning also for 90 degree trenches is also so shrapnel doesn't continue down the tunnel it will embed itself in the wall of the first corner created.
I think you mean embed as inbred means something else entirely.
Trenches also have 90-degree corners because they provide cover when the enemy raids the trench, A corner will also deny the enemy a long line of sight.
@@Dhunter83 Both valid points, and I scrolled down to the comment section because I was *sure* that they'd fuck up these two aspects. Thanks for confirming my hunch.
Sad thing (or mindboggling thing?) is that we nowadays have "simulation" video games where such elemental factors play no role. Instead we learn that you exit you plane in mid-flight, shoot an enemy plane with your Panzerfaust (or whatever, "Panzerfaust" or "Panzerschreck" are just ubiquitous in these games because they sound so badass German super-science), and then board your plane again.
Was. Der. Fick.
Wouldn't a rounded corner do the same thing?
@@HalNordmann A round corner would be less effective.
There are several reasons to dig trenches that way.
They might dissopate the blast wave from a shell, but most casualties did not come from blast waves, but from shrapnel, and shrapnel will most certainly not go around corners.
A second reson is that if the enemy manges to enter your trench, they will not have a clear shot down the length of the trench.
One reason the trenches were dug in straight sections with 90⁰ angles is that they were often dug under fire, and each section needed to join up with another section of trench, dug by another group of soldiers. Digging a wavy trench like a sinewave, is really difficult because you have no easy reference point, and you don't want to climb out of there to see if you are getting it right.
With the pattern they used, you can dig 30 yards, turn 90⁰ left, dig 30 yards, turn 90⁰ right, and so on. The soldiers can work by measuring tape and a compass, no need for advanced mathematics.
But that tells us nothing about whether you can kinda cut the corner a bit once your a few feet from the other section.
@@petergerdes1094 They reason they didn't cut corners was because these trenches almost always had the sides reinforced with planks/logs/concrete to prevent them caving. It's a lot easier to attach to planks/logs/concrete at 90 degrees then it is to bend planks/logs/concrete around a curve. Any man with a T square can make a corner, but only a highly skilled craftsman can make a curved line with wood or stone.
When I was in the Army we were told that angling trenches was to prevent shrapnel spread. Blast needs to go 'somewhere', and follows the line of least resistance, so we presumed that the angles would also help, but not by absorbing blast, rather by slowing it laterally, this meaning there would be less resistance to it vertically = it goes up... 👍
Shockwaves travel further to get to you or through a wall of dirt
Another reason especially with anything more than muzzloading can clear a trench fairly hastily if the trench is straight, they can fire down the entire length
Angled trenches also prevent your soldiers from being in enfilade if the enemy were to take part of it.
When you were in the Army, did the still teach trench warfare to general infantry? Reason I'm asking is I with Ukraine, trench warfare has become increasingly relevant; I saw a post from a foreign fighter (not sure if they were a Solider or Marine) stated that when serving in the US, he was never taught anything about trench warfare because the US tries to avoid that situation entirely (and the focus of the last 2 decades was on COIN operations).
Edit: Shorted a sentence for clarity.
I'm assuming that they also taught you that you should not be able to see a third section of trench from the one you are in. If you look at the "serpentine" trench, you can see a straight line through the curve to the next straight. My reading as a kid told me trenches on the Western Front zig-zagged in basically uniform lengths, not the little kinks between straights seen here.
@@aaronleverton4221 hard corners give soldiers cover to peak round when others reach it instead of being fired upon as soon as they reach your trench
Zigzag trenches are better for attaching a position, using full bends leaves some parts easily fired upon from a bit of height
Zigzags give some cover at all times when advancing
I miss this show.
Rest In Peace, Grant.
Sadly relevant in this day and age, over 100 years after WW1.
Same was looking for this comment, R.I.P
You do know there is a war in Ukraine.
Sorry. I misread that comment.
Ruscist imperialism could have been prevented through deterance. We could have learned from history, we chose not to.
@@apokkalyps6yeah, maybe we could have learned from history where you have periodic attacks on Russia from the west, be it by Swedes, Teutons, Polish-Lithuanis, France, Great Britain, Germany or US... the take away here would be the folks who use swastika clad aholes are no better then them...
Haven't heard of the corners being used to protect against blast wave, but I have heard that it helps against shrapnel and it is easier to protect your trench against the enemy too. If the enemy took over a straight trench then they could easily shoot everyone in it, but if it has corners, then you take over only one corner at a time.
Originally the trenches were built zig-zag so you couldn't just shoot a cannon straight down the line. Especially because the trenches (saps) were dug to get close to castle walls during sieges so you wouldn't get everyone obliterated by cannon fire.
@@killerkonnat indeed, and later during world war 1 it turned out to be a good protection against strafing airplanes for the same reasons
Without watching the video yet. I was about to come to say exactly same. Corners protect against shrapnel and enemy bullets if they get to the trench. I don't think it can stop blast wave ever, in best case slow it down maybe. But shrapnel and bullets it will stop for sure. Those can't make it around the corners. Of course same way those corners help to protect the enemy that has got in to the trench, but it provides small chance of survival for both sides compared to none in straight trench. In direct fire is anyway one of the used methods even in modern days and shrapnal from those. And to be honest situation is pretty bad if enemy is in the same trench that one tries to prevent them to getting to.
@@EsaNuutinen it is even more important against shrapnel than against blast wave, since the lethal radius of shrapnel goes much further than the blast wave's lethal radius
The whole myth is about the importance of *SHARP CORNERS* - straight trench is just a control.
4:40 Diddy was already buying out all the baby oil even back then!
GOD DAMMIT YA BEAT ME TO IT!
Beat me to it
THOUGHT THE SAME THING
DAMN IT! I was like what are the odds! YOU BEAT ME TO IT!
Bruh i was gonna type that
man, BBC's MasterChef has changed drastically.
Of course that's a joke right? Lol
@@gosie-z Watermark in the top right of the picture
under-rated comment
This video is cooked
@@TheMovieLoftTechnically it's burnt in
The 35mph to a dead stop is a lot more severe than most accidents, usually you’re hitting something with a little more give than a planet.
Yeah I thought that, even a lot of buildings would probably be "softer"
Had the exact same thought. Many many people survive car accidents at even higher speeds. 35 mph seems weak for a crash.
4:46 somewhere Diddy is dry
I came to say the same thing. Lmao
Diddy is very wet. Where do you think all the baby oil went?
4:34. Did you check Diddy's place? There must be some oil left there.
My brain immediately said “no diddy” when I saw the baby oil
I paused to make a similar comment.
lol that was my first thought too. "thats cuz diddy bought all that shit dawg"
Them baby oil jokes hit different right now😂😂😂
I wish there were un-cable-tv cut versions of these series.
Yeah, i always disliked the "2 steps forward, 1 step back" editing formula of TV.
I used to watch a lot of Mythbusters and River Monsters back then, but the formula got really tiresome.
At least you can skip through a lot of it now, but i have been thinking about editing my own versions of shows sometimes, either by cutting out Tory, Kari and Grant if they were doing something useless, or vice versa.
And indeed, cutting away all of the "coming up" and the post ad-break recaps.
But the other channel does have some "Best of" episodes that cut away a lot of the fat.
But they even turned a control test into a cliffhanger in this episode, which actually made me go: "Really?? A control test cliffhanger, come on."
I mean, i get it, it's a car crashing down, spectacular footage, but still, it was still only just the control.
I originally watched these on German TV, it was a completely different experience 😆
Just like there's barely any canned laughter in the sitcoms broadcast on German TV. I think I remember one in the 90s where they didn't have any of that, just a lot of awkward pauses 😂
@@Games_and_Musicthere's a YT channel called "Mythbusters for the impatient"
It already exists, go type it in and watch them there.
I’m looking for a gift for my aunt.
@@Henipahstrong reference
Haven't ever heard it suggested before that the purpose was to stop blast waves. My understanding is trenches are angled to limit casualties from shrapnel and enfilading fire along an entire position should it be flanked.
And let's remember many artillery shells were airburst, designed to rain shrapnel down into the trench over a wider area, as well as the blast force.
The Maori used zig zag trenches against the British 50 years before the famous trenches of WWI
The intro, with the best moments, it ALWAYS hits me in the nostalgia. And they are all different. Amazing work, this show.
I think the thing people are getting hung up on in the straight trench is that they aren't thinking about the situation right. The explosion and its pressure wave are very fast, and the straight trench is effectively a giant resonating chamber for it. The similar experiment in air and sound would be a long tunnel and echos, compared to an anechoic chamber compared to an open field compared to a normal room. A large open room is not the same as an open field, because it does eventually have walls that rebound sound. An anechoic chamber is the closest compared to an open field because it dampens and attenuated sound waves. The long, sealed tube will be the most echoic, because it has no place to dissipate sound. This is the effect of the trench, it magnifies the blast by confining it, the other two bent trenches diffuse the blast upwards and into the earth, cutting out a lot of the overpressure the straight trench will feel.
Yeah, they effectively invalidated the experiment with their trench construction. Not only did they fail to account for the shockwave reverberating within the trenches, they built 2 with plywood panels and 1 without, meaning that the shockwave would behave differently in 2 of the 3 trenches.
P Diddy had the rest of the baby oil!!
Damnit you beat me to this comment 😠
lol me too
WANTED TO COMMENT EXAT SAME THING LMAOOOO
Tbh, this is the first time I ever hear about trench corners being about pressure waves. To me it was always about shrapnel, which undoubtedly will be stopped by any corner whatsoever.
As a video game player, to me it was always about obscuring line-of-sight😂 Now that i think about it for more than 2 seconds that makes 0 sense
@@literallyjustgrass Well, there is some point to it in the case that enemy infantry enters you trench. If you had one long trench, a single machine gunner could mow down everyone inside. Apart from that, line of sight is always also a pathway for shrapnel, so you weren't entirely wrong.
shrapnel and not having a straight line to be strafed by a plane or machine gun down the entire length
@@literallyjustgrass thats also part of it, if a machine gunner got into a straigh trench it would be a turkey shoot
Just seems like an all-round good idea really. Reduces the pressure wave, reduces the travel distance of shrapnel, inhibits line of sight for attackers, prevents strafing attacks from above, allows sections to hold out and be used for counterattacks even when others fall.
they should have tested if a normal airbag would be enough to make that fall survivable, it looks vicious and might be too harsh
Good question to ask.
To be honest, I thought they were effective at higher speeds. Fascinating.
"For unbelted occupants the effectiveness goes to zero or becomes negative above 40 kph (25 mph) for MAIS 3+, and for belted occupants the effectiveness stays positive but with significantly lower magnitude for speeds above 40 kph (25 mph)."
pubmed.ncbi.nlm.nih.gov/16210197/
It won't. I worked on polymer "springs," for a safety device years ago. The problem is even with an ideal material with perfect compression ratios at the speeds they were testing the body needs to decelerate over a longer distance than is possible in a car crash. The balloons/airbags/ are decelerating the body to a stop over a few inches... your organs/brain just slam into your ribs and skull. You wont go through the windshield or hit the stirring wheel and have external bleeding necessarily, but your skeleton is the backstop for the liver, ribs, kidney, heart brain, etc...
It's probably just easier to make sure you don't continue a straight path through a serpentine when digging with sharp corners.
Dig Width x and make a 90 degree bend continue 2times as long as width x and start another 90 degree bend.
Making things round serves no extra purpose and would introduce errors, so 90 degree bends are just more efficient.
Also note that German trenches are NOT 90degree walls, but tapered down. Less digging, roomy for your upper body, supports leaning and bracing to shoot and allows pressure and shrapnel to release up, rather than amplify down.
The grammar of these titles are progressively getting worse
The titles for the timestamps are bizarre too. I’m guessing they’re using AI for these
Grammar of comments progressively worse
Hah, yeah, i noticed it in a previous upload as well.
same thing happening on the other channel, "banijay science"
Yh, "Do trench corners save lives" would've been fine. 'Soldier' is implied.
These guys are remarkable not only for studious study, but the ability to work together and accept a new idea from a member is to be tried. Excellent science.
26:36 for the iconic scene.
Squeak squeakedy squeak squeakin’ 🫡
The money shot
I love her
Holy crap they are putting full episodes on TH-cam now? Absolutely awesome!
Now we know why that was all the baby oil available LOL
4:34 this has aged so well 😂😂 we finally know where the Baby-oil went 😂😂😂
i wouldnt say "well" 😬 (😂still funny though [the baby oil bit, not the cases])
Only 12 bottles?? Diddy must have been in town!! 😂😂
Idk how the numbers at 47:45 makes sense. 76, 60 and 397 are all in a straight line, so shouldn't all of them have similar numbers? It's not before the second set of numbers where we should start to see real differences, no?
Could be the reflected blast wave
@@MushookieMan I don't really think so. The blast wave at the very end of the straight trench is down to 21 psi. Even if all of that comes straight back, you'd expect to see 97psi (if you use the 10ft value from the curvy-cornered trench and assume that none of it was reflected back).
I'd bet the 397 was caused by some piece of lumber or something hitting the measuring apparatus.
I had a close look a the numbers. The 397 is clearly an outlier.
The 60 vs 76 show that there's a 20% margin of error in the strength of the shock wave that goes down the trench. The 60 is right before a sharp corner, from which most of the shock wave would be reflected, and the 76 is before a round corner, which should reflect less of the shock wave back (if that even has an effect on the 10ft numbers). (Also, 20 ft along the straight trench you have 65psi, while you have only 60psi after only 10ft along the sharp-cornered trench. That also can't be the case without some variability in the shock wave strength.)
The remaining numbers along the curved and sharp-corned trenches are well within that 20% margin of error of each other, meaning that we really can't be certain that the corner shape helped.
But here's the actually interesting result: If you compare the open ground results versus those in the two cornering trenches, you see that the numbers inside the trenches are still higher (and by more than 20%). This means that the trenches still "conduct" the pressure wave. As in, the pressure wave can't just have "jumped out" of the trench, traveled over top of the cornering section, and gotten refracted or reflected back into the trench.
Meaning both the sharp-angled and the curvy corners are far from perfect.
Somehow that charge was too powerful
Possibly an incorrect mix or perhaps substituted a different explosive
If they only planned the 3 trenches and tacked the flat ground “control” at the last minute the substitute would probably have been a plastic explosive instead of a less common granular high explosive that would be more ww2 authentic
@@Pystrocan't help but wonder if you could add a T intersection to every straight to dissipate some of the pressure
Can anyone explain why the first tunnel's explosion produced such a high PSI at 20ft compared to the other two? Surely all three trenches are the same up to 20ft, then they turn - so my assumption is that the pressure wave would be the same up until the first corner, but clearly not?
Doesn't make sense to me. Doing the math on the reduction in pressure the straight trench is reduced by a factor of 1/20th compared to 1/10th on the others.
The reason why the blast pressure in the straight trench was so much higher than in the open-air test was because of the internal reflections of the blast wave in an enclosed space. In the open air where the blast wave can expand in almost 360º, it follows the inverse square law like a sound wave's amplitude. However, in the trench, all that energy is redirected and focused down the tube, almost like speaking through a long tube will amplify the volume in a single direction.
@@ChrisvanderMerwe_cw3 I get that, but my point is that, up to 20ft, the three trenches are identical, right? So why are the blast pressures so radically different between them
I think it's about ripple/scattering and air compression.
As the wave moves through clean air unhindered, it seems to be the most potent.
But maybe if the wave nears a wall, air pressure starts building up from being pushed towards the wall, and in turn pushing back a little on the wave or creating a bit of an air cushion, on top of also colliding with the wall.
The bouncing back might also explain why the straight trench seems to lose so much bite so quickly, as it just keeps on moving relatively unhindered.
But then i wonder if all the tests moved at the same speed, as in, did the sensors go off at the same intervals, or was the straight trench pressure wave quicker than the rounded or squared one?
@@ChrisvanderMerwe_cw3 Yes that would certainly account for some increased pressure but not 10 times more. The exact same distance of 20 feet straight is in all the examples but only one of them has a 10x increase.
… kind of eerie how a 2011 episode about events circa 1917 has something so relevant to 2024…
war didnt magically end in 1945
The plywood and dirt walls would absorb and reflect shockwaves differently, so one with half of it being bare dirt walls would alter the results.
great episode thanks for posting this . i had to pas it along to the mythbusters group so others can watch it as well its great to see the full episodes i hope you make more of them available to be watched here in the usa without having to get a vpn to watch them . rest in peace sir Grant i wish mythbusters had a Star on the walk of fame
Nice to see Grant Imahara (October 23, 1970 - July 13, 2020) again,
Damn, I had no idea
He passed away? He was that old? When I watched Mythbusters I thought he was like, 20, 30 tops.
@@yutahkotomi1195 He also worked on Star Wars
@@yutahkotomi1195 He died of an aneurysm bro what. Do you think age is the only reason people pass away?
@@aspookyscaryskeleton1474 No need to be snippy, age is the usual after all, followed by fat people.
We miss you Grant. Happy to see this show again
I know the trench myth is the main focus in the episode, but it really didn't seem like the three of them understood airbags at all. You're not trying to stop the person, you're trying to slow them down, and you're trying to do it from full speed to a stop. Dropping the car was more or less fine, but the weight tube to do the mini tests starts from nearly rest. They also seemed to think the balloons popping was a bag thing when it's the other way around: The balloons popping gives more time to decelerate the person/weight. I think it would've been more interesting if they understood that before doing the tests, because this felt like an "egg drop" challenge assignment for school when they hadn't paid attention during class
It's not that the balloons popping is bad, but that they're popping before they're able to have much of an effect. However, they definitely used that test incorrectly. In the control, the weight has the entire length of the tube to accelerate due to gravity before it faces any resistance. After that, it meets its first resistance almost immediately, meaning the higher you stack the balloons the lower the force applied to them at first contact. The balloon animals were literally touching the weight mechanism when it was released. A nearly useless experiment.
4:34 Adam doing his P.Diddy impersonation
I came here immediately for the p diddy jokes as soon as Adam mentioned that he couldn't find any more baby oil.😅
26:38 = most paused moment in this episode...
4:45
To answer where the Mythbusters got all of their baby oil, here’s special guest P Diddy!
It's like diddys house with all that baby oil😂
I’m so glad you published this show! 🙏
I have friends in Ukraine for whom this is a very practical concern, thank-you for reposting this. People need to be reminded this is a thing today, not just in WWI and WWII.
I mean in this day and age its all sense less, you can spend a week in a foxhole, think your safe to come out and in a second a drone will touch down and kill you.
If any thing, the Ukrainians are more than adapt at building trench networks, just like the Russians are.
people who need this are trained for it in war lol we don't need to be reminded of anything besides for entertainment stfu
Same, I have a friend in Ukraine as well. He is Russian
A russian in Ukraine? Oh, he's either a good russian or will soon be 😉
@@MytyaPrykhod There is also a (small) chance that he is a Russian volunteer fighting for Ukraine. A Czech firearms instructor buddy of mine did train a group of Belarusian volunteers that had joined the Ukraine side back in the early days of the war. So I suspect there will also be some Russians.
You know, having watched some footage from Ukraine, I'm inclined to say that it's about shrapnel, not necessarily about the shockwave.
It's about shrapnel. If a shell lands in your trench, its a bad day no matter what the corners are.
It’s about shrapnel, defending a trench AND blast
@@josephfoulger9628 exactly, multiple things can be true.
@@guesswho2778 also to prevent enemies from shooting down the trench
@@STURYANPHUAYEWLIANG Yeah I've seen combat footage from Ukraine where the Ukranians and Russians are in the same trench no more than a few meters away from eachother but beacuse the trenches aren't a straight line they can't shoot eachother and they can sit in the same trench holding the angles and throwing grenades at eachother for half an hour or more. Sometimes it is only decided by a fpv drone coming and doing a precision strike, or one side retreats rather than going around the corner or climbing out of the trench towards the enemy since it means very likely death.
For the ballons tests: in the control, the driver (with seatbelt) experienced a 150G, after the improved balloons test, the clown only experienced a 130G load. Meaning that it would be more beneficial to tightly pack some strong balloons in front of you instead of wearing a seatbelt!
2:22 the germans, or anybody, never thought corners were for shockwave protection. when an artillery shell explodes it throws metal shrapnel everywhere. a corner stops the shrapnel from flying straight down the trench, killing or wounding everyone. instead only the people in the section that got hit catch shrapnel.
But... trenches rarely had flat walls. They had parapets, dugouts, drainage ditches, in-wall bunks, ammo shelves, sandbag steps, ladders, and, of course, bodies.
There can also be partitions made of sandbags
P Diddy wants his baby oil back.
The balloon one being busted doesn't make sense, cause in their test the driver clown with seatbelt also died in the impact
They drop was too high
Yeah, and they should have tested with an actual air bag as a control, I have a feeling it wouldn't fare that much better. Looking at the numbers alone, going from 500-600 or whatever it was down to 150 should have made the myth at least plausible.
I was thinking the same thing. Their control had a seatbelt also not be sufficient to survive. So their test was trying to show that balloons were better than modern safety equipment, not that it could save your life.
Also, that their last test were worse than the big balloons were telling.
In their shop test, they effectively went for the stiffest setup, as that would hinder the dropping weight accelerate as it was dropped just above the balloons. The weight should have been at significant speed compared to the acceleration when the impact happend.
The further distance the body travels during stopping, the less g's, so the big balloons where the nose just barely touched the windscreen was about as perfect an impact as one could hope for, no matter the safety equipment.
They were basically testing to see if they could make it safe, while doing a drop height where the total crumble zone was insufficient to ensure survivability no matter how well cushioned the passenger was.
The reasoning for that being all the baby oil San Francisco had that day was due to P Diddy buying out all the baby oil🤣💀 4:40
4:34 should ask diddy’s help
If you want to reduce shockwave and pressure, you should give a " V " shaped trench a try. Rectangular trench funnels the blast wave, amplifying it. " V " shaped trench projects the blast wave outside the trench. I pretty sure it will make a significant difference.
Don't mind me, just re-living my childhood.
Grant was such an amazing person
Containing blast is one thing. Containing shrapnel is quite another. Most angles will contain shrapnel. To contain or dissipate blast you need the equivalent of a silencer on a gun. That is lots of paths to exit the blast safely before it propagates down the trench line,
To stop shrapnel you want vertical trench walls perpendicular to the direction of the enemy, a corner like that results in a piece of trench that goes towards the enemy, which is bad for shrapnel protection.
Shrapnel not fragments, are often used synonymously today but if you talk about a WWI context real Shrapnel shells were in use and popular during the early part of the war. They are fundamentally a canister with bullets fired from an artillery piece that separate in the air close to the target by small bursting changes. Practically it is like a large shotgun that is fired from the air at a relatively flat angle toward the ground. A deep trench with a vertical wall defeated them and they became obsolete during WWI
High-explosive shells produce fragments, not shrapnel. The corners are to stop the pressure wave and the fragment from a shell with high-explosives, not shrapnel
The difference between fragments or shrapnel might be irrelevant in today's context but is very important in a WWI context.
@@target844corners prevent fragmentation, which is what the guy is talking about. If a shell lands inside the trench, the fragments shred that section but go no further as they embed themselves in the corner wall.
The corner did not significantly degrade it's defensive capability from ground fire, since people in the trench would still be below the level of the ground
It's also to help the defenders and prevent an enfilade. If the enemy captures one end of a straight trench -- they own that trench as far down as they can shoot. But if the trench has corners, the trench can be defended from the attackers at each corner.
The "plausible" rating on the trench thing when the difference was literally just one PSI at each measure point between the sharp and rounded corners... That's the definition of margin of error.
Also, there is no reason for the 20 feet pressure to be much higher in the curved trench compared to the sharp one.
th-cam.com/video/Milnou63Dyg/w-d-xo.htmlsi=6iV9zJeW37dmzM3O&t=2889
Was thinking the exact same thing 1-2 PSI is a margin of error. I'm also confused as to how the straight trench amplified the blast 10x within 20 feet but the other two were significantly lower within the same 20 feet straight. It seems that the 50ft mark is roughly 10% of the 10 feet mark except for the straight where it's only 5% of the initial blast.
There's proceedural and other errors (often serious) in all their experiments, which invalidate the vast majority of their results. One day, people will learn that they are not authorities and this isn't science, no matter how many times they use that word.
They messed up when they decided the curved trench wouldn't have wood all the way. It's very possible that the bare dirt absorbed more pressure than the wood panels. Given what they are capable of making, they should've made curved wood panels.
This would be the difference between "plausible" and "confirmed".
There were issues with the experiments as was the norm in Season 9.
4:32 P-Diddy got alerted.
4:30 "This is all the Baby oil San Fransisco had today" ... This sentence gave me whiplash as I was watching this classic episode. Man, who would have ever thought such a mundane and intentionally silly sentence would be so creepy many years later...
In no ways is this an accusation, but it's more just a sad example of how context can change simple perceptions.
Yeah I heard that and immediately thought “I think I know where all the other baby oil went” oof
You think Diddy is the reason SF didn't have baby oil at the time? watching this now that is the funniest part to me
Trench corners were not just for subduing explosions, but also to stop rifles being fired down the length of the trench and make the trench easier to defend against an attacker who had got in to the system.
They got all the baby oil in san fransico, more like pdiddy roughed up xD
@4:35 this is a comment that aged spectacularly
Great timing.
4:35 after all the diddy stuff i think we now know why adam could find any baby oil😂
Something about the straight trench doesn't add up. For the control and the two cornered trenches they all follow a pattern roughly 30ft 1/3, 40 ft 1/5 and 50ft 1/10 however the straight is 30ft 1/6, 40ft 1/10 and roughly 1/20th of the blast at 50ft. Mathematically the straight reduces the blast more but for some reason the initial blast was significantly higher.
It might have something to do with scattering?
I also thought that the initial blast seemed too great compared to its dropoff.
But, seeing how the other 2 trenches had similar dropoffs, i think that with the straight trench the harmful waves keep bouncing away from the blast relatively unhindered, whereas the other 2 trenches provide a little bit of a "noisy feedback" because of the opposing angles.
Because, it's designed to stop the wave from moving forwards, so, some of it will be scattered back, but altogether less harmful than an unhindered explosion.
@@Games_and_Music Great theory however doesn't account for the above ground sample. it too followed the same drop off as the cornered trenches. More so the first 20 feet of all the trenches is the same but only the straight one had 10x the PSI compared to the control/above ground while the other two trenches were roughly 2x.
@@DiustheZ Fair point, the control would've been the worst if unhindered alone was the answer.
Maybe, as i just "realized", it could also be like a firecracker effect.
Where the gunpowder itself ignites fairly powerfully, but it becomes a lot more when confined, packed tight.
That the straight trench also acts a bit like a barrel, an air cannon or something,
I would also not want to be jumping over that trench when the explosion goes off.
Not sure what bent firecrackers will be like, so i'm not sure how well the analogy works.
Just throwing spaghetti against the wall.
might be a matter of the shockwave bouncing back and forth along the length of the straight trench causing interference with itself that amplify the pressure at certain points. While both the bendy trenches would reduce that by bleeding off energy round the corner each time the shockwave hit the wall at the bend and bounced back
@@WhichDoctor1 That's more than certainly the cause of the increase over the above ground control. Problem with that explanation purely for the straight trench 10x increase is the 20ft straight is exactly the same on all three trenches. The blast would be travelling one way through the trench and wouldn't travel backwards. Theoretically the blast should be the same on all the 20ft straights regardless of what is after it. Once the initial blast passes the sensor it doesn't come back.
Wonder if a trench with a Z profile might reduce the blast shockwave at the other side even more.
blame diddy for the lack of oil!!!!!!!
I know everyone's saying the shrapnel is what really matters, but I think shockwaves are no joke. I remember in 9th grade I was playing sports on the school field and I was right in the middle when a powerline transformer blew from the field edge. To my surprise, I felt a pretty hard _THUD_ hit my chest from the blast wave, and that was just a powerline transformer.
26:09 most replayed, wonder why
This episode will be used in court as diddy's defense for having so much baby oil.
Blame the lack of oil on Diddy.
That Sean Connery impersonation at the beginning was on point Adam!
Edit: 4:20
I thought it was so an enemy soldier couldn't fire bullets down the length of the trench.
That's why the trenches aren't completely straight, to stop bullets and fragments. Those two it doesn't matter if the corners are sharp or a bit rounded. The blast pressure of a shell is kind of insignificant compared to fragments, so even if the sharp corners do make a difference to the blast I'm not sure if they really matter much overall.
It's pretty terrifying thinking about the energy equivalence driving at a 'mere' 35mph with the speed you achieve dropping 42 feet vertically onto your face.
Is the baby oil the reason youtube thought I wanted to see this video in 2024?
I love in the intro: “Let’s chop this car up!”
*cut to the runaway chopped up car*
I think we know who else was buying all the baby oil. A certain rapper perhaps
as much as I watched this show, when it was on TV, I am not sure how I missed this episode.
When they said Germans said right angled trenches were better, I immediately thought 'probably true then'. Great episode, great show!
I've been in a restored German trench on a WW1 battlefield. It was a sine wave with woven wicker wall linings. The British trenches were the ones with ninety degree corners and corrugated roofing iron walls.
36:00 I'm reasonably confident that there is a tiny niche audience who were made very happy with the Kari segment there.
My friend has a huge crush on her, not me though. Ewwww. Who wants a hot girl who buids and blows stuff up for fun? 😛
26:38..
@@zechsblack5891 okay class how about we all stand up, stretch, get ourselves a glass of water and just stare out the window for a sec.
19:44 ‘As evenly-as-possible’ *pffft* those balloons are gonna go *vrrrrrrk*
14:07 - That's what she said!.....and by Adams look, you know he was thinking it too
I miss myth busters awesome show with great people.
4:38 nah diddy has it on premium
How can it be 397 psi for the straight trench but 60 psi on the straight part of the cornered trench?? something isn't right with their sensors...
i agree it seems high. But i think it's right that it is higher in the straight trench because in the angled trenches there is relatively less resistance for the pressure to go vertical.
They likely took the wrong measurement from the 20ft sensor in the straight trench. The blast probably went through the sensor initially, but then rebounded off of the end of the trench and came back. At the same time, the blast also rebounded off the wall behind the explosives and came forward, for some reason meeting there most strongly. That was likely the highest reading from that sensor, but also probably not the first reading. I would bet that if we saw the full reading from the sensor it would have jumped to around 60 before spiking to 400 a few milliseconds later.
The 2 sign, which is the first sensor reading (they discarded the sensor at 10ft/sign 1), is behind the corner. Can see this at 45:19
@@aimerw Yeah, it works like a gun barrel, meaning all the energy that doesn't go up in the air is funneled down and the trench.
Waves can have additive and destructive interference. It might be that the sensor was exactly on a peak where all reflections added up. Back wall, end of the trench and both sides. It is a lucky shot but not impossible
nah, not the fucking baby oil 💀 4:30
Kary's balloons had an odd shape!
As for the main myth: The place I live in is fairly angular, the hallway looks a lot like those 90 degree trenches. And airwaves travel through it flawlessly in one direction. I can follow entire conversations held at the other end of the apartment but no one even hears me scream. Smells too, they propagate throughout the entire place and die in my room
I think the trench "myth" deserves better than plausible. In fact, I think if you had added a ballistics gel dummy with waterfilled cavaties inside of it at the far end of each trench, it would have gotten a passed-stamp.
Also, another reason for adding bends to a trench is that it slows down attackers trying to clear it when they have to move carefully due to not having good visuals around the bends, as well as providing the defenders with defensive points negating attempts to clear the trench system out.
WWI trenches often had wood reinforcement on the sides, It is a lot simpler to have sharp corners then any curved variant, just put a vertical pole in the corner and have the horizontal planks behind it. You can do that with other angles than 90 degrees too, it will just not be a curved corner.
Wood on the wall prevents them collapse in from for example rain. It also provides better protection from both Shrapnel shells or the relatively primitive time fuzed that could be used to airburst shells. It also makes it possible to have a narrower trench. The flatter the trajectory of a shell the header it is to get into the trench if it is narrow with vertical walls. There is a reason mortars with a trajectory that is close to vertical when they hit the target become popular
@@target844 I wonder is not a negative to wood reinforcement that it produces more shrapnell compared to dirt when hit? Like shattered wood flying all around at a high speed?
@@serganta8861 Not really. The mortar or artillery shell would have the most shrapnel and would almost certainly kill anyone in the section of trench it landed in. Past the 90 degree corner, the damage to the wood would be negligible. It's also worth noting they used plywood instead of thicker, firmer planks. Plywood is much easier to break.
@@squashiejoshie200000 Thx for the info :)
The myth they were testing wasn't how useful corners were (since their application against shrapnel and gunfire is obvious), they were testing whether or not those corners had to be *sharp* or not.
I mean... with a difference of 1 PSI, I don't imagine it would make THAT big a difference. If you're the poor sod whose trench got a direct hit around the corner, you'd probably just be happy you weren't a few meters down the line.
It is exactly what u though, they diference is just 1 psi, You wil be dead anyways.
not the babyoil kekw
Trench corners aren't just for pressure waves they're also for shrapnel
I feel the crash was too severe. They should have dialed it down to the point that the clown with the seat belt survived even if just barely.
Also, dropping a car is not the same as a crash
It seems so, but i guess the big one left out is the airbag.
I guess crashes are a lot more lethal without the airbag.
I thought that cars should be tested to be safe in crashes at certain speeds, 35 doesn't seem to be excessively fast, but yeah, the airbag might be the big difference.
they said they chose to do it at that height because in the myth they were at normal driving speeds, which the team assumed to be around 35mph (see 10:25) -- their calculations supposedly showed that dropping the car from that height would result in that speed at impact (Tori mentions it at 33:02)
@@LophoWilli Tori and the narrator talk about this at 11:35; they said it's easier/safer to perform the test in this manner than just have a car floor it towards a wall. Also, the directions of the forces acting on the driver/passenger in this test would likely be similar to those experienced in an actual car crash (in both cases the force would act from the front of the car inwards, acting to push the passengers into their seats)
@@daksmyth9320 But even a wall gives a tiny bit as it bows out. They were smashing it into a steel plate on solid ground.
26:38 was an incredible awakening for my teenage self.
4:47 Now that is awesome. Also usefull for in the classroom.
Grants multi-layered balloon / bubble wrap: slather some shaving cream on it to make a massive, reuseable cream pie. Then give it to Moe Howard.
I crasht my car at 35 mph headson to a tractor and im stil allive without seatbelt or airbag, hit my head in the windshield tho. Still enjoying the headaches today.
@@woofernl I’m glad you got lukcy.
Short extensions past the right angle also decrease the blasts as it results in destructive interference.
26:38 Wow.
A bend waveguide dissipates energy from the guided wave... This is true for any type of wave through any type of waveguide. Be it an optical fiber, a grammophone or in this case a trench. They could do the experiment also with a sound source but explosions are simply wayyy more fun.
Nowadays people just drop grenades on top of soldiers in trenches using drones anyway so I guess blast pressure doesn't matter as much
yeah but shrapnell travelpath matter a LOT (at least to the other soldiers around.)
So still best to dig sharp trenches. (and maybe get a roof)
The grenade launcher was developed by the Indian Army in 1915 for the same purpose. Fire the grenade into the air to rain down in to the trench.